Triple glazed window suppliers

I recommended Green Building Store to a friend (not the friend trying to get her loft insulated, I have loads of friends wanting to improve their homes and not knowing where to start and who to trust). She’s looking for two windows, French Windows and a front door, which seems like a reasonable sized order. They have told her that import costs would be ‘disproportionately large’ for a project of this size, so are declining to quote.
Has anyone else had this response? Is it Brexit or inflation or something else? Can anyone recommend a good alternative who can supply at a household level ?

Brexit may play a part. I was quoted a few years ago for a front door and surround only. There was a separate item on the quote for import costs (including freight) and they exceeded the the cost of the door etc. I suggested that I was willing to wait until they had another order being delivered in my area and piggy back off that but they weren’t interested. I still have my old door. It is double glazed but is 1978 vintage and could be improved upon.

Maybe the next green cooperative needs to be for the manufacture of windows and doors that actually do the job and not just look pretty in a sales brochure.

If you look up buildings in the Passivhaus register you will find the window supplier recorded there. The trouble is some excellent companies, such as Munster, don’t do retrofit at all, let alone a one off window or door.

Hi Sian.

I’ve not come across that before, but then haven’t needed a quote since covid began…

You could try, a great company based in Manchester getting windows from Estonia.

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I’ve used Internorm windows before, the first importer was crap and went bust, but the windows themselves are excellent!! We’ve used Spectrum Architectural this time and they’ve been great, they’re even holding the windows for us as we’ve had some delays with the rest of the building work. Ask for Silje :slight_smile:

Hi I had the same response from the Green Building store when I asked about 2 windows and a door…

I got mine from

No issues with minimum orders and cheap if not free delivery.

I couldn’t find anyone to install them so am doing it myself with help.

15 windows and 1 front door and 1 set of french doors came to £11k, about 33sqm. I’ve gone for triple glazed aluclad. Some of them have been in a year and I’m pleased so far.

They often have sales which are genuine, eg. Black Friday was a genuine discount. The website will always say 40% off which is the discount compared to velfac etc. Sometimes the discount for patio doors goes up to 65% off.

Happy to explain a bit more about installation but it takes about 4 days work per window taking into account the removal of plaster, making an airtight connection to the house and then insulating the reveals.

Just a note that they are very heavy - 30kg per sqm. Our front door weighed over 70kg and even the lightest window was 40kg.


We had a good experience with Green Building Store, but we are a couple of stops down the M62 from them so were a local job they could fit in around other jobs. And the great thing is they have their own fitters. We’ve also had windows from Ecospheric, but delivery and fitting was a problem. Their Viking windows come ready-glazed so are often too heavy for your local joiner to deal with.
There are local joinery manufacturers who will make triple glazed frames, but I’ve not found one that double seals the opening lights like the imported ones have.

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Good to hear they work well, I’ve always been impressed with their website, it’s my go to if I want a quick guestimation of a window cost!!

Thanks for all suggestions. Will pass on.

Has anyone on this forum found a supplier of shaped doors to fit an existing arch?

To fit in a rectangular door and fillers each side it either needs to be adequately wide but too short or sufficiently high but too narrow to carry anything through.

Edit: This is not an ancient listed building so I do still have the option of removing the arch and going rectangular. I expect I’d get used to it. It would probably be a lot cheaper than a bespoke arch.

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Do you know what U value the windows and doors are please? I can’t find it on their website. Thanks

Ignore me, I’ve found it says 0.7-0.8w/m²K


Hello Anyone find an alternative to Green Building Store who will both supply and fit windows in UK? I have just read the above thread and looks like ecosperic have a minimum of 5 windows (according to their website). I am replacing two bedrooms windows. Klarwindows seem to only supply. Any other ideas. I was considering Keystone Windows in Chesterfield their Velfac range (found trustpilot poor review) or Timber windows (mixed) and local joiner (who could not be detailed in specification) so I am feeling a bit lost. Is Norrsken any good? Would dearly like to have a more local option Manchester area or Yorkshire. Be most grateful for help. Happy to pay more for quality. Many thanks

Velfac is a Danish company if I remember correctly. Try looking them up and look for other suppliers. I haven’t used there windows myself but have seen a load in use in office blocks.

Unless they have changed in the last couple of years Munster Joinery don’t do retrofits in the UK.


Thanks Tim
We have a quote in progress with Keystones Chesterfield for Velfac replacement windows but was stopped in my tracks by their very poor trustpilot review. Hard to know how relevant that is but it was very negative. Hence my looking further afield beyond Velfac. Velfac dont seem to align with Passihaus methods. Would anyone else recommend/use Velfac? Would focusing on companies that use Passihaus methods/standards be a good plan? Any other thoughts? Many thanks

Whilst Velfac are a good make and a vast improvement on typical UK window manufacturers I would recommend Passivhaus windows if you can get them. They also aid your progress to EnerPHit if that is your ultimate target.

Nearly all Passivhaus windows are made abroad and although you can sometimes get a good price on the windows you have to add the transport and import costs, which for a small order can exceed the cost of the window.

I have said elsewhere on this forum that some sort of cooperative is needed to correlate orders and hade a central delivery address from where the smaller orders can be collected. That would save on freight and import administration costs.


I have experience with Velfac windows for the community building i help to manage.
They have to be made specially, and be installed by a recommended installer of which there aren’t many.
In our case it’s Direct Installations in Denton. So you would be reliant on them - Keystones? Are you satisfied with them?